Seems like today FRP is the last word in game programming with Haskell. Do you know something that could be a good tutorial, or at least introduction to FRP ? Something that could somewhat help me learn the ropes, 'cause I'm afraid if I dive directly into your code I'm gonna be lost. I don't think there's any material on FRP that could be considered a general tutorial, because there are many flavours with smaller and bigger differences, and no-one really seems to know how to program in this manner beyond toy examples. So, for the time being, I'd probably start with the original Fran paper [1], which is quite accessible in my opinion, and even though some of the details are obsolete, it explains the basics reasonably well. The Yampa Arcade [2] is probably the best introduction to the arrow-based approach (AFRP). The new Reactive paper [3] is not beginner friendly, but if you already grokked Fran, it shouldn't be too hard to follow, and it describes a way to design an applicative style reactive library with a much cleaner interface than that of Fran.
Gergely [1] http://conal.net/papers/icfp97/ [2] http://www.haskell.org/yale/papers/haskell-workshop03/index.html [3] http://conal.net/papers/push-pull-frp/ -- http://www.fastmail.fm - A fast, anti-spam email service.